Emissions of air pollutants derive from almost all economic and societal activities. They result
in clear risks to human health and ecosystems. In Europe, policies and actions at all levels have
greatly reduced anthropogenic emissions and exposure but some air pollutants still harm human
health. Similarly, as emissions of acidifying pollutants have reduced, the situation for Europe's rivers
and lakes has improved but atmospheric nitrogen oversupply still threatens biodiversity in sensitive
terrestrial and water ecosystems. The movement of atmospheric pollution between continents
attracts increasing political attention. Greater international cooperation, also focusing on links
between climate and air pollution policies, is required more than ever to address air pollution.